Health.com: 18 Most Sickening Food Ingredients

Antibiotics

What it is: Silicon dioxide is what gets in your bathing suit and your hair at the beach. Affectionately known as sand, it’s also found in food. “It’s used in a lot of things as a flow agent and partly because it does a nice job of absorbing a little bit of atmospheric humidity that would cause clumping in a variety of things,” says Milkowski. Swallowing a little sand at the shore probably never hurt you and it probably won’t hurt you at the dinner table either.

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News about gross-out ingredients like pink slime and ammonia (more about both later) got us thinking: What other surprises lurk in the food we eat? We put that question to food safety as well as food manufacturing experts, and it turns out all kinds of things go into refined and processed foods that you wouldn’t willingly put in your mouth. Here's a few...read at your own risk!

That’s not to say it isn’t safe to eat. The Food and Drug Administration and other agencies spend lots of time and energy to make sure you’re not eating stuff that will kill you. But the idea that something seems “just plain wrong” often isn’t part of the calculation.

What it is: Vegetarians prepare to be shocked! The same stuff that puts the jiggle in Jello and other gelatin-based products is derived from collagen, a protein often collected from animal skins.

The source varies depending on the type of food, says Andrew L. Milkowsi, PhD, adjunct professor of animal sciences at the University of Wisconsin Madison. The gelatin in desserts, for instance, comes mainly from pig skin.

Where you’ll find it: Gelatin, which is a thickening agent, can also be found in frosted cereals, yogurt, candy, and some types of sour cream. (Check the label.)

What it is: Mechanically separated meat is what’s left over after the meat clinging to the bones of chicken or pork are forced through a sieve-like structure using high pressure. “It looks like a paste or batter,” says Sarah A. Klein, a staff attorney with the Food Safety Program at the Center for Science in the Public Interest. “You have crushed bits of bone and cartilage and other things that can end up in that final paste.”

Because of the risk of bovine spongiform encephalopathy (BSE) or mad cow disease, mechanically separated beef is no longer allowed in human food.

Where you’ll find it: Some hot dogs and other products (again, check the label)

What it is: We have carbon monoxide detectors in our homes for a reason: this odorless gas can be deadly. But the same stuff that comes from the exhaust pipe of your vehicle is also used in packaging ground beef and some fish like tilapia and tuna. It helps them retain their youthful blush, says Patty Lovera, assistant director of Food and Water Watch.

Where you’ll find it: Carbon monoxide is injected into plastic wrap after all the air is sucked out to block the process of oxidation that can turn pink meat brown. The process is considered safe for humans although it isn’t widely used anymore, says Lovera. Consumer groups have objected to the treatment's potential to mask meat spoilage.

What it is: Candy lovers, cover your eyes: pretty, shiny treats like jelly beans come at a price. They're often coated with shellac, a sticky substance derived from secretions of the female Kerria lacca, an insect native to Thailand.

Where you’ll find it: Shellac makes jelly beans, candy corn, and other hard-coated candy look shiny. It may be called a “confectioner’s glaze” on the packaging. So sweet, and yet so sick.

What it is: Saltwater is fine in the ocean, but injected into food? Believe it! Too much salt can contribute to high blood pressure and other health problems, so less is better. But in a practice called plumping, manufacturers inject salt and other ingredients into raw meat (mostly chicken) to enhance flavor and increase the weight of the meat before it’s sold.

Where you’ll find it: In packaged meat, and you should avoid it! Check the fine print and the nutrition facts label. Meat that’s been injected may say “flavored with up to 10% of a solution” or “up to 15% chicken broth.” Regular chicken has about 40 to 70 mg of sodium per 4-ounce serving, while plumped chicken can contain 5 times or more than that amount, or 300 mg and up.

What it is: Don’t viruses make us sick? Well yes, but bacteriophages —tiny bacteria-killing viruses—actually help us by making bacteria sick. First approved for use on food in 2006, bacteriophages infect food-contaminating germs, not humans, says Milkowski.

Where you’ll find it: Manufacturers spray these on ready-to-eat meat and deli products that are sold in sealed plastic pouches. The bacteriophage products come in two types: One that combats E. coli and the other Listeria bacteria. (Only the second is used on food; the first is used to spray cattle.) Check the ingredient list for the words “bacteriophage preparation."

What it is: Pink slime is a product derived from the bits of meat clinging to fat, which are separated out by melting the fat away and spinning in a centrifuge.

The result is a pinkish substance called lean finely textured beef that’s treated with ammonia gas to kill germs, and then added to ground beef as a filler. Lots of ground beef, as in 10 billion pounds per year.

Where you’ll find it: Recent furor over the concoction has caused companies like Wendy’s and McDonald’s to report that their hamburgers are pink slime-free and some supermarkets like Safeway and Wegmans to say they will no longer carry it. Schools participating in the National School Lunch Program now have the option of ordering beef without it, according to the USDA.

What it is: Though the chemical bisphenol A, or BPA, has been removed from most hard plastics (including baby bottles and sippy cups), it can still be found in the sealant in the lining of some cans, says Lovera.

Where you’ll find it: “This can be especially problematic with acidic foods like tomatoes,” she says. “The concern is that it leaks into foods.”

BPA has been linked to brain, behavior and prostate problems, especially in fetuses and children.

What it is: Brace yourself—this food flavoring is extracted from the castor sac scent glands of the male or female beaver, which are located near the anus. According to Milkowski, the substance is pretty expensive (think about what it probably takes to obtain it) and is more common in perfume than in actual foods.

Where you’ll find it: While it sounds downright disgusting, the FDA says it’s GRAS, meaning it’s “generally recognized as safe.” You won’t see this one on the food label because it’s generally listed as “natural flavoring.” It’s natural all right—naturally icky.

What it is: Did you ever take a slug of soda or juice and feel a tingling sensation in your throat? That may be sodium benzoate. This common preservative is also generally recognized as safe (GRAS) by the FDA, meaning it shouldn’t pose a hazard. That doesn't mean you shouldn't avoid it: a 2007 study published in The Lancet found that a mixture of sodium benzoate and food dyes was linked to hyperactive behavior in children, although it was hard to tell if the dyes or the preservative were to blame.

What it is: Silicon dioxide is what gets in your bathing suit and your hair at the beach. Affectionately known as sand, it’s also found in food. “It’s used in a lot of things as a flow agent and partly because it does a nice job of absorbing a little bit of atmospheric humidity that would cause clumping in a variety of things,” says Milkowski. Swallowing a little sand at the shore probably never hurt you and it probably won’t hurt you at the dinner table either.

What it is: Yup, insects again. In your food. When it comes to food, insects are handy for other things besides their shine. They’re good for color too, especially red. Carmine is a red food-coloring that comes from boiled cochineal bugs, which are a type of beetle.

There have been reports that the bug-based coloring can cause severe allergic reactions in some people, including potentially life-threatening anaphylactic reactions, so the FDA now requires that the ingredient be listed clearly on food and cosmetic labels.

Where you’ll find it: Carmine can be found in ice cream, Skittles, Good n’ Plenty, lemonade, and grapefruit juice.

What it is: This chemical is found in antifreeze, it’s true. But, says Milkowski, “it’s a very, very safe material.” In fact, it’s much safer than a kissing cousin, ethylene glycol, which is particularly toxic to dogs.

Propylene glycol has lubricating properties which aid in making spice concentrates, not to mention condoms. And if you need good mixing in food, this is your compound. “You’ll find things that don’t mix well in water do disperse well in propylene glycol,” says Milkowski.

What it is: Cellulose, derived mainly from wood pulp and cotton, is used in paper ­manufacturing—and sometimes added to food.

Where you’ll find it: Cellulose is added to shredded cheese to keep the strands from sticking together, and also can be found in ice cream. It’s found naturally in corn. Cellulose is “is very innocuous material,” says Milkowsi. “Humans can’t digest it.”

What it is: Do you eat seaweed? If you said no, prepare for a surprise, because carageenan is everywhere. Extracted from seaweed, carrageenan is a gel used as a thickening agent and emulsifier (keeps food from separating.)

Where you’ll find it: May be injected into raw chicken or other meat as a way to retain water, as well as in dairy products like cottage cheese and ice cream. Chocolate milk often contains carrageenan to keep the cocoa from separating from the milk.

What it is: We worry about smoking and eating too much smoky barbecue. We also wonder, what exactly is liquid smoke, anyway? Liquid smoke is made by burning sawdust and capturing the components in either water or a vegetable oil, explains Milkowski.

Where you’ll find it: The resulting product can be purchased and added to sauces and other foods to give it that—yes—smoky flavor. If you’re used to cooking on an open fire, this might not seem all that gross to you, and manufacturers certainly don’t shy away from it. Liquid Smoke is also added to barbecue products, baked beans, hot dogs, bacon, and beef jerky, among others.